Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: qual é o máximo de frete (toneladas métricas) com o aeroporto sendo liverpool
 ###Tabelas: CREATE TABLE 2006_data (2006_data_id AUTO_INCREMENT PRIMARY KEY, Rank INT, Airport VARCHAR, Total Passengers INT, % Change 2005/2006 VARCHAR, International Passengers INT, Domestic Passengers INT, Transit Passengers INT, Aircraft Movements INT, Freight (Metric Tonnes) INT) CREATE TABLE head-to-head_records_against_other_countries (head-to-head_records_against_other_countries_id AUTO_INCREMENT PRIMARY KEY, Games INT, Wins INT, Draws INT, Losses INT, Goals For INT, Goals Against INT, Goal Differential VARCHAR) CREATE TABLE list_of_provincial-level_divisions (list_of_provincial-level_divisions_id AUTO_INCREMENT PRIMARY KEY, GB VARCHAR, ISO № VARCHAR, Province VARCHAR, Chinese Name VARCHAR, Capital VARCHAR, Population¹ INT, Density² VARCHAR, Area³ INT, Abbreviation/Symbol VARCHAR) CREATE TABLE chinese_taipei_national_futsal_team (chinese_taipei_national_futsal_team_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Venue VARCHAR, Score VARCHAR, Competition VARCHAR, Report VARCHAR) CREATE TABLE singles:_14_5–9 (singles:_14_5–9_id AUTO_INCREMENT PRIMARY KEY, Outcome VARCHAR, Date VARCHAR, Championship VARCHAR, Surface VARCHAR, Opponent VARCHAR, Score VARCHAR)  
SELECT MAX Freight (Metric Tonnes) FROM 2006_data WHERE Airport = Liverpool